A High Voltage Power Supply's output (HVPS or hereinafter referred to as just a “power supply”) is typically output voltage regulated, so that the output voltage remains relatively stable over a wide range of output currents that varying the load may present to the unit. This is called Voltage Mode (VM) regulation. Additionally, the output current of the power supply may be limited to some maximum current while still in the VM region, either for the protection of the power supply itself or the load, or both. Once the threshold of VM has been passed, the power supply then would go into Current Mode (CM) region of control, where a decrease in load resistance does not cause an increase in current output, but rather causes a decrease of voltage output, while holding the output current constant. Therefore, in some applications, it would be highly desirable to have a circuit displaying more slope, that is, less steep slope in the CM region of the power supply curve.
At times, it is necessary to have the CM slope something other than near vertical. The current application approaches this problem with two novel solutions; both aimed at maintaining highest efficiency, and lowest cost.
In this respect, before explaining at least one embodiment of the invention in detail it is to be understood that the invention is not limited in its application to the details of construction and to the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. In addition, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.